Known are pistols CZ-83 made by the manufacturer C̆eská zbrojovka Uherský Brod, the Czech Republic, and pistols SIG-Saurer P 230 made by the manufacturer J. P. Saurer GmbH, Germany.
These are self-loading-pistols, whose barrel is fixedly and non-movably mounted on a frame. During the firing process, the locking of a barrel channel till the moment of the ejection of a bullet out of the channel and a pressure drop of powder gases take place due to the force of inertia of a massive slide and due to the force of a recoil spring, maintaining the slide during shooting in the frontmost position.
The important features of the above-mentioned pistols include a high degree of accuracy of shooting, since the barrel is fixedly mounted in the frame of the pistol, and the simplicity of the mechanism.
On the other hand, the fact that it is not possible to use high performance ammunition for shooting a pistol with such a locking system appears to be a serious drawback, since to be able to use such ammunition, it would be necessary to increase considerably the weight of the slide, which would lead to an increase in the weight of the whole pistol and would result in a great slide impact force between the slide and the pistol frame on reaching its rearmost position after the shot.
Known is the patent CZ 304686 dated Aug. 22, 2014 and the utility model CZ 25812 dated Aug. 27, 2013 “Lock of a slide of a self-loading-pistol”, in which the locking member is formed by a cylinder in a seat of a rigid pistol frame and is forced upwards by a locking spring. Its upper portion extends to the travel path of the locking face of the pistol slide. Consequently, during the firing process, the locking face of the slide leans against a cylinder, which is forced upwards by a locking spring arranged below the cylinder. That secures retaining the opening movement of the slide, which allows the bullet to be ejected out of the barrel channel before it opens.
The advantage of the above-mentioned mechanism of closing the barrel channel during the firing process is primarily its simplicity and also the fact that the barrel can be mounted fixedly in the frame, which permits shooting with a high degree of accuracy.
However, the system has a drawback—namely the inability to pull the slide manually backwards to supply a cartridge from the magazine to the cartridge chamber of the barrel when loading, since during this operation it is necessary to press on the stiff locking spring through the cylinder.
An aim of the invention is to provide a pistol for shooting with high performance ammunition, whereby the barrel of the pistol is fixedly and non-movably mounted on the frame to ensure the accuracy of shooting. The automatic pistol must ensure the reliable locking of the channel of the non-movable barrel until the moment of the bullet exiting the barrel channel and the pressure drop of the powder gases without increasing the weight of the slide and of the whole weapon. The pistol design must provide for a possibility of unrestrained cocking of the slide to supply a cartridge to the barrel during loading.